Conventional safety razors have a blade unit connected to a handle for a pivotal movement about a single pivotal axis which is substantially parallel to the blade or the blade edge. For example, U.S. Pat. Nos. 7,197,825 and 5,787,586 disclose such a razor having a blade unit capable of a pivotal movement about a pivot axis substantially parallel to the blade(s). The pivotal movement about the single axis provides some degree of conformance with the skin allowing the blade unit to easily follow the skin contours of a user during shaving. The pivot axis, which usually extends parallel to the cutting edges of the blades, can be defined by a pivot structure where the handle is connected to the blade unit. Such safety razors have been successfully marketed for many years. However, the blade unit often disengages from the skin during shaving as it has limited ability to pivot about the single axis.
To address this problem, it was suggested that the blade unit can additionally pivot about another axis which is substantially perpendicular to the blade(s). For example, U.S. Pat. No. 5,029,391 discloses such a razor having a blade unit capable of a pivotal movement about a pivot axis substantially perpendicular to the blade(s). It is disclosed that the blade unit can carry out a pivoting movement about two axes, so that the safety razor blade unit can optimally conform to the contour of the face during shaving. Other examples of safety razors which have a blade unit capable of pivotal movements about two pivot axes are disclosed in U.S. Pat. Nos. 6,615,498; and 5,953,824; and Japanese Patent Laid Open Publication Nos. H2-34193; H2-52694; and H4-22388.
While it is disclosed that these razors help the blade unit to more suitably follow the skin contours of a user, they tend to have a complicated structure to implement the pivotal movements about two pivot axes and thus cause a difficulty in manufacturing.
Thus, there is a need for a safety razor having a blade unit capable of a pivotal movement about a pivot axis substantially perpendicular to the blade by a simpler manufacturing process, compared to the prior art technologies. There is also a need for a shaving cartridge having a blade unit capable of a pivotal movement about a pivot axis substantially perpendicular to the blade by a simpler manufacturing process, compared to the prior art technologies.